Re: [PATCH rdma-rc v3] RDMA/core: Always release restrack object

[Jason Gunthorpe]

On Tue, Jun 29, 2021 at 09:49:33AM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@xxxxxxxxxx>
> 
> Change location of rdma_restrack_del() to fix the bug where
> task_struct was acquired but not released, causing to resource leak.
> 
>   ucma_create_id() {
>     ucma_alloc_ctx();
>     rdma_create_user_id() {
>       rdma_restrack_new();
>       rdma_restrack_set_name() {
>         rdma_restrack_attach_task.part.0(); <--- task_struct was gotten
>       }
>     }
>     ucma_destroy_private_ctx() {
>       ucma_put_ctx();
>       rdma_destroy_id() {
>         _destroy_id()                       <--- id_priv was freed
>       }
>     }
>   }
> 
> Fixes: 889d916b6f8a ("RDMA/core: Don't access cm_id after its destruction")
> Reported-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
> ---
> ---
> Changelog:
> v3:
>  * Dropped controversial hunks and updated commit message respectively
> v2: https://lore.kernel.org/lkml/e2eed941f912b2068e371fd37f43b8cf5082a0e6.1623129597.git.leonro@xxxxxxxxxx
>  * Added bug report analysis
> v1: https://lore.kernel.org/linux-rdma/f72e27d5c82cd9beec7670141afa62786836c569.1622956637.git.leonro@xxxxxxxxxx/T/#u
> ---
>  drivers/infiniband/core/cma.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied to for-next, thanks

Jason